1. Field of the Invention
The present invention relates to a control system for an automotive air conditioner, and more particularly to a control system for an automotive air conditioner for automatically regulating the temperature of conditioned air discharged from outlets according to solar insolation.
2. Description of the Related Art
In conventional automatically-controlled air conditioners for automobiles, it is a general practice to automatically correct the temperature of conditioned air discharged from outlets according to solar insolation through a solar insolation sensor.
On the other hand, a radiation heat from the sun is transmitted to the driver in two ways: one is a directly body-transmitted solar insolation component which is a solar insolation by sun light directly entering/transmitting from windows of a vehicle to the body of the driver; and the other is a vehicle applied solar insolation component which is a solar insolation transmitted to the body of the driver via air inside a driver/passenger compartment. Heat is mainly applied to the upper half portion of the body of the driver with the directly body-transmitted solar insolation component, and the rate of its heat transfer is largely influenced by the orientation and elevation angle of the sun (refer to FIG. 2). On the other hand, with the vehicle applied solar insolation component heat is applied to the whole body of the driver, and the rate of its heat transmission is not influenced by the orientation of the sun as much as with the directly body-transmitted solar insolation component but is influenced only by the angle of elevation of the sun (refer to FIG. 3). In FIGS. 2 and 3, the location of the sun relative to a left front seat is expressed on the axis of abscissas in which zero degree represents a solar insolation entering from the front forward, xe2x88x9290 degrees a solar insolation entering from leftward relative to the center of the vehicle body, +90 degrees a solar insolation entering from rightward relative to the center of the vehicle body, and 180 degrees a solar insolation entering from rearward. In particular, it is found from the graph in FIG. 2 that the rate of heat transmission reaches its peak by a solar insolation entering from a side window on one""s seat side (for example, a driver""s seat side) with the sun being located on the one""s seat side when the sun is situated at a relatively high position (or at an angle of elevation of 60 degrees) and that the rate of heat transmission reaches its peak by a solar insolation entering from the windscreen with the sun being located on an opposite side to the one""s seat (for example, a passenger""s seat side) when the sun is situated at a relatively low position (or at an angle of elevation of 30 degrees).
In the prior art, however, the temperature of conditioned air discharged from the outlets has only been corrected/adjusted simply according to the solar insolation sensed by the solar insolation sensor, and since an adjustment/correction of the solar insolation value is not done based on a positional relationship between the sun and the one""s vehicle, as well as locations of the outlets, for example, in the event that the positional relationship between the sun and the one""s vehicle is such that the body of the driver is not subjected to the solar insolation while the solar insolation sensor is subjected to the solar insolation, an adjustment/correction of the solar insolation is done based on the solar insolation received by the solar insolation sensor.
Namely, according to the conventional control system for an automotive air conditioner, the solar insolation heat received by the driver does not necessarily coincide with an extent to which the air conditioner is controlled depending upon the location of the sun. For example, in the event that the temperature is set so that the driver can feel comfortable at the upper half portion of his or her body, there is caused an excessive amount of cold air to be applied to the lower half portion of the driver""s body, or in a state in which sun light is applied to the driver""s seat while the front-passenger seat is shaded from direct sun light, it becomes impossible to control the temperature of the driver/passenger compartment so that both the driver and the front-seat passenger can feel comfortable sufficiently.
The invention was made to solve the problem inherent in the prior art, and an object thereof is to provide a control system for an automotive air conditioner which is improved so as to increase further the comfortableness of the driver and passengers.
With a view to attaining the object, according to a first aspect of the invention, there is provided a control system for an automotive air conditioner wherein a target temperature for conditioned air discharged from outlets is calculated from a detection value of an in-vehicle temperature sensor (6), a detection value of an ambient temperature sensor (7) and preset temperatures (4, 5) and wherein the temperature for conditioned air discharged from outlets is corrected with a solar insolation correction coefficient based on a solar insolation detected by a solar insolation sensor (2). In the control system, the solar insolation correction coefficient comprises two types of values one of which is a value (11L, 11R) expressed by a directly body-transmitted solar insolation component which is a solar insolation directly received by the body of a driver and/or a passenger whereas the other is a value (12) expressed by a vehicle applied solar insolation component which is a solar insolation received by a vehicle to thereby increase the temperature of a driver/passenger compartment.
According to this configuration, the target temperature for conditioned air discharged from the outlets can be set in such a manner as to correspond to the solar insolation which the driver actually receives.
In addition, according to a second aspect of the invention, there is provided a control system for an automotive air conditioner wherein a target temperature for conditioned air discharged from outlets is calculated from a detection value of an in-vehicle temperature sensor, a detection value of an ambient temperature sensor and preset temperatures and wherein the temperature for conditioned air discharged from outlets is corrected with a solar insolation correction coefficient based on a solar insolation detected by a solar insolation sensor. In the control system according to the present invention, there are provided outlets disposed at upper and lower positions and selector member for selecting the upper and lower outlets, and in that the solar insolation correction coefficient for correcting the target temperature for conditioned air discharged from the upper and lower outlets comprises two first and second values.
According to this configuration, when the temperature is set so that the driver can feel comfortable at the upper half portion of the body thereof to which the solar insolation is applied, the temperature can be set so that the drive can also feel comfortable at the lower half portion of the body thereof to which no solar insolation is applied.
Additionally, according to a third aspect of the invention, there is provided a control system for an automotive air conditioner as set forth in the second aspect of the invention, wherein the target temperature for conditioned air discharged from the upper outlet is controlled by a total value of the two values whereas the temperature of conditioned air discharged from the lower outlet is controlled only by the second value. Furthermore, according to a fourth aspect of the invention, there is provided a control system for an automotive air conditioner as set forth in the second aspect of the invention, wherein there is provided selector member for allowing conditioned air to be discharged simultaneously from the upper and lower outlets, and wherein the temperature of conditioned air discharged from the upper outlet is controlled by the first value whereas the temperature of conditioned air discharged from the lower outlet is controlled by the second value. Moreover, according to a fifth aspect of the invention, there is provided a control system for an automotive air conditioner as set forth in any of the second to fourth aspects of the invention, wherein the first value is a value adapted to vary according to the location of the sun whereas the second value is a value which is constant in general irrespective of the orientation of the sun. Thus, according to the configurations as set forth in the second to fifth aspect of the invention, the temperatures of conditioned air discharged from the outlets into the driver/passenger compartment can be controlled in a more precise fashion so as to optimize the environment inside the driver/passenger compartment.
Furthermore, according to a sixth aspect of the invention, there is provided a control system for an automotive air conditioner wherein a target temperature for conditioned air discharged from outlets is calculated from a detection value of an in-vehicle temperature sensor, a detection value of an ambient temperature sensor and preset temperatures and wherein the temperature for conditioned air discharged from outlets is corrected with a solar insolation correction coefficient based on a solar insolation detected by a solar insolation sensor. In the control system according to the present invention, there are provided outlets disposed at upper left and right and lower left and right positions and temperature adjusting member for individually adjusting temperatures of conditioned air discharged, respectively, from the upper left and right and lower left and right outlets, and in that the temperatures of conditioned air discharged from the upper left and right outlets are controlled by left and right individual correction values which correspond to the location of the sun whereas the temperatures of conditioned air discharged from the lower left and right outlets are controlled by a value which is common to the conditioned air discharged from the lower left and right outlets irrespective of the orientation of the sun. According to this configuration, the temperatures of conditioned air discharged from the outlets of the air conditioner can be optimized in every condition.
The invention may be more fully understood from the description of preferred embodiments of the invention, as set forth below, together with the accompanying drawings.